Adhesive earplugs useful for sealing the ear canal

ABSTRACT

Systems and methods are provided for sealing an ear canal for retaining a solution in the ear canal. Adhesive earplugs are provided through which the solution can be delivered, and which, following delivery, retain the fluid in the ear canal. The systems and methods may also be useful for delivering an anesthetizing solution to the ear canal of a human patient and for maintaining the solution therein for use with an iontophoresis system for anesthetizing the tympanic membrane.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 13/827,403, filed Mar. 14, 2013, entitled “AdhesiveEarplugs Useful for Sealing the Ear Canal,” which claims priority to andthe benefit of U.S. Provisional Patent Application No. 61/653,080, filedMay 30, 2012, entitled “Adhesive Earplugs Useful for Sealing the EarCanal,” the contents of each of which are incorporated herein byreference in their entirety.

TECHNICAL FIELD

The present invention is generally related to medical devices andapparatus and in particular, for devices and methods for filling andretaining a solution in the ear canal of a human patient.

BACKGROUND

The present invention provides systems and methods useful for deliveringfluids to the ear canal of a patient. The systems and methods may beuseful for anesthetizing the tympanic membrane and/or the ear canal of apatient in preparation for a surgical procedure, including the placementof a tympanostomy tube (or pressure equalization tube) across a tympanicmembrane of an ear. Additionally, the invention provides systems andmethods for delivering and/retaining fluid in the ear canal of a humanpatient for treatment of the ear canal or tympanic membrane.

Otitis media is among the most common diagnoses made by pediatricians. Amajority of children may have at least one episode of otitis media (“earinfection”) prior to their third birthday. Otitis media is often causedby an inability of the Eustachian tube to drain fluid from the middleear. Otitis media is often treated with antibiotics.

A significant number of children exhibit recurrent episodes of otitismedia and/or otitis media with effusion. Treatment of these more severecases often involves the placement of a tympanostomy tube across thetympanic membrane to provide adequate drainage and/or ventilation of themiddle ear and reduce the likelihood of future infections. Tympanostomytubes provide fluid communication between the middle and outer ear(e.g., pressure equalization) and typically fall out spontaneouslywithin about a year of placement. Tympanostomy tube placement is amongthe most frequent surgical procedures performed in the pediatricpopulation. It has been estimated that more than a million tympanostomytubes may be placed each year, with typical patients being between about18 months and 7 years of age at the time of the procedure.

Tympanostomy tube placement is typically performed in an out-patientsurgery setting under general anesthesia. After administering thegeneral anesthesia, the physician typically first examines the externalauditory canal and tympanic membrane under microscopic visualizationthrough a hand-held conical shaped speculum. The physician then makes anincision in the tympanic membrane (a “myringotomy”), typically using astandard, small profile scalpel which the physician advances through theconical speculum. The physician may then pass a suction device throughthe myringotomy into the middle ear, to aspirate fluid/effusion from themiddle ear. The physician will then place the tympanostomy tube acrossthe tympanic membrane, typically using a basic tool, such as forceps,for holding and advancing the tube into the myringotomy.

Systems and methods have been proposed for deploying tympanostomy tubeswithout having to use general anesthesia. Such systems are described forexample in US Publication No. 2011/001564 (Tympanic Membrane PressureEqualization Tube Delivery System), US Publication No. 2010/0198135(Systems and Methods for Anesthetizing Ear Tissue), US Publication No.2009/0163848 (Iontophoresis Methods) and US Publication No. 2009/0262510(Disposable Iontophoresis System and Tympanic Membrane Pain InhibitionMethod) each of which is incorporated by reference in their entirety.These publications describe integrated methods for deliveringtympanostomy tubes and appropriate anesthesia, however, simplifiedsystems that provide for delivery of solution to the tympanic membranewith minimal discomfort to the patient are still desirable.

In light of the above, the present inventions are directed to improveddevices, systems, and methods for delivering and retaining fluid in theear canal of a patient. These improvements facilitate delivery andretention of an anesthetizing solution into the ear canal to prepare thetympanic membrane for tympanostomy tube placement without requiringmultiple devices and operator-performed steps. At least some of theseadvantages may be provided by the embodiments described herein.

SUMMARY

The present invention provides systems and methods for use in deliveringa solution to and retaining a solution in the ear canal of a humanpatient.

In one aspect, the invention is directed to an earplug having a domeshaped portion for insertion into the ear canal. The dome shaped portionhas an outside surface and an inside surface. The earplug further has aflap useful for removal of the earplug from the ear canal. A pressuresensitive adhesive on the outside surface of the dome shaped portioncontacts the ear canal such that the earplug is retained in the earcanal for a period of time.

In one embodiment, the earplug has a flange that surrounds the domeshaped portion. In another embodiment, the flange is a 360 degree flangethat surrounds the dome shaped portion and in yet another embodiment,the flange is a 180 degree to less than 360 degree flange that partiallysurrounds the dome shaped portion.

In a further embodiment, the earplug flange has notches, and in anotherembodiment the flange has 1 to 6 notches.

In yet another embodiment, the earplug has a shaft portion forconnection to a handle through which the solution is delivered into theear canal, the shaft portion being contained within the inside surfaceof the dome shaped portion.

In another embodiment, the pressure sensitive adhesive on the earplug isselected from the group consisting of silicones, acrylics, butyl rubber,ethylene-vinyl acetate, natural rubber, nitriles and styrene blockcopolymers.

In yet another embodiment, the pressure sensitive adhesive is a siliconepressure sensitive adhesive.

In a further embodiment, the solution is selected from the groupconsisting of an anesthetizing solution, an antibacterial solution, anantifungal solution, an anti-inflammatory solution and a ceruminolyticsolution.

In still another embodiment, the solution is an anesthetizing solutionthat is selected from the group consisting of lidocaine, the combinationof lidocaine and epinephrine, and the combination of lidocaine,epinephrine and sodium bicarbonate.

In another aspect, the invention is directed to a system for deliveringa solution to the ear canal of a human patient and for retaining thesolution therein. The system includes an earplug for use in retaining asolution in the ear canal of a human patient, the earplug having a domeshaped portion for insertion into the ear canal. The dome shaped portionhas an outside surface and an inside surface, a flap useful for removalof the earplug from the ear canal, a shaft, and a pressure sensitiveadhesive on the outside surface of the dome. The system further includesa handle for inserting the earplug into the ear canal of the patient,the handle being inserted into the shaft of the earplug and having afill system wherein the solution is delivered through the handle and theshaft of the earplug into the patient's ear canal.

In one embodiment, the earplug has a flange that surrounds the domeshaped portion.

In another embodiment, the handle further has vent features. In afurther embodiment, the vent features may be vent holes or vent slits ora combination thereof.

In another embodiment, the handle further has a fill tip.

In still another embodiment the handle further comprises electrodesuseful for iontophoretic delivery of the solution to the tympanicmembrane.

In yet another aspect, the invention is directed to a method for fillingand retaining an anesthetizing solution in the ear canal of a humanpatient. The method includes preparing an anesthetizing solution,preparing the ear canal of a human patient for delivery of theanesthetizing solution, selecting an earplug having adhesive thereonbased on the determined appropriate earplug size, assembling an ear kitsystem using the selected earplug, inserting the earplug into the earcanal of the human patient and adhering the earplug to the ear canal,and powering on a control unit to begin an iontophoresis procedure todeliver the anesthetizing solution to the tympanic membrane.

In one embodiment, the anesthetizing solution is selected from the groupconsisting of lidocaine, the combination of lidocaine and epinephrine,and the combination of lidocaine, epinephrine and sodium bicarbonate.

In another embodiment, preparing the anesthetizing solution includeswarming it to body temperature.

In yet another embodiment, assembling the ear kit system includesremoving the earplug with adhesive thereon from a packaging system,exposing the adhesive, and positioning the earplug.

In another aspect, the invention is directed to a method of filling andretaining a solution in the ear canal of a human patient. The methodincludes preparing a therapeutic solution, preparing the ear canal of ahuman patient for delivery of the therapeutic solution, selecting anearplug having adhesive thereon based on the determined appropriateearplug size, assembling the earplug on an ear kit system using theselected earplug, inserting the earplug into the ear canal of the humanpatient and adhering the earplug to the ear canal, wherein the solutionis selected from the group consisting of antifungal agents,antibacterial agents, anti-inflammatory agents, antibiotic agents,steroids, astringent, and ceruminolytics.

In another aspect, the invention is an earplug system for use inretaining a solution in the ear canal of a human patient. The earplugsystem comprises an earplug having an outside surface for contacting theear canal. The earplug comprises a dome shaped portion for insertioninto the ear canal, a flap connected to the dome shaped portion; and apressure sensitive adhesive adhered to the outside surface of theearplug. The earplug system further comprises a handle for inserting theearplug into the ear canal; and tubing for delivering the solutionthrough the earplug and the handle and into the ear canal. In oneembodiment, the earplug system further comprises a pressure applicatorfor activating the pressure sensitive adhesive and in anotherembodiment, the earplug system further comprises a liner for protectingthe pressure sensitive adhesive during storage and insertion of theearplug into the ear canal.

In one embodiment the earplug system tubing is routed through the handleand exits the handle at an angle of between about 10 and 30 degrees. Inanother embodiment, the earplug system conforms to different anatomy. Inyet a further aspect the solution is an anesthetizing solution.

In another aspect, the invention is a method for retaining a solution inthe ear canal of a human patient. The method comprises providing anearplug system comprising an earplug having an outside surface forcontacting the ear canal. The earplug comprises a dome shaped portionfor insertion into the ear canal; a flap connected to the dome shapedportion; and a pressure sensitive adhesive adhered to the outsidesurface of the earplug. The earplug system further comprises a handlefor inserting the earplug into the ear canal and tubing for deliveringthe solution through the earplug and the handle and into the ear canal.The method further comprises inserting the earplug system into the earcanal and delivering the solution into the ear canal.

For a further understanding of the nature and advantages of theinvention, reference should be made to the following description takenin conjunction with the accompanying figures. However, each of thefigures is provided for the purpose of illustration and description onlyand is not intended to limit the scope of the embodiments of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a frontal view of an outer ear.

FIG. 1B shows a partial cross-sectional view of an outer, middle andinner ear.

FIG. 2 shows a system for iontophoretic substance delivery.

FIG. 3 shows a bottom view of an earplug according to one embodiment ofthe invention.

FIG. 4 shows a perspective view of the earplug shown in FIG. 3.

FIG. 5 shows a perspective view the earplug of FIG. 3 further includinga handle according to the invention.

FIG. 6 shows a perspective view of the earplug and handle of FIG. 5further including the accompanying wire and tubing for iontophoreticsubstance delivery.

FIG. 7 shows a perspective view of a package for storing the earplug ofFIG. 3.

FIG. 8 shows a method according to the invention.

FIGS. 9A, 9B, 9C and 9D show perspective views of a method for fillingthe ear canal according to the invention.

FIGS. 10A, 10B, 10C, 10D and 10E show perspective views of a furthermethod for filling the ear canal according to the invention.

FIGS. 11A, 11B, 11C, 11D and 11E show perspective views of a number ofdifferent embodiments of the earplugs according to the invention.

FIG. 12 is an enlarged cut-away view of an earplug including a handleaccording to a further embodiment of the invention.

FIG. 13A shows a perspective view of an earplug assembly according toanother embodiment of the invention.

FIG. 13B is an enlarged cut-away view of the earplug and handle of theassembly shown in FIG. 13A.

FIGS. 14A and 14B are perspective views of adhesive earplugs accordingto an embodiment of the invention.

FIG. 15 is an enlarged view of the inside of the earplug of the earplugassembly shown in FIG. 13A and 13B.

FIGS. 16A, 16B, 16C and 16D are top views of the inside of varying sizedearplugs useful according to the invention.

FIG. 17A is a top view of a liner useful with the earplugs of theinvention, and FIG. 17B is a perspective view of two liners in placeover an earplug according to the invention.

DETAILED DESCRIPTION

The embodiments of the invention are intended to provide systems thatare useful for delivering and retaining a solution in a patient's ear.

FIG. 1A shows a view of an outer ear 10. The outer ear 10 includes amajor element known as the auricle 100. The outer ear serves as a funnelfor directing sounds into the internal portions of the ear. The majorphysical features of the ear include the lobule, 102, concha 104,anthelix 106, helix 108, scapha 110, triangular fossa 112, tragus 114,antitragus 116 and ear canal 118.

FIG. 1B shows a cross-section of the inner and outer portions of theear. The outer ear 10 is shown connected to the ear canal 118. The earcanal is shown as a relatively straight passage, but is often a morecurved, tortuous passageway. The ear canal is connected to the middleear 120, which includes the tympanic membrane 122. The middle ear 120 inturn is connected to the internal ear 124 which leads to the auditorytube 126 (also known as the Eustachian tube). The middle ear 120normally has a pocket of air behind the tympanic membrane 122. When themiddle ear 120 is infected, fluid swells inside the tympanic membrane122. Fluid expansion causes extreme pain to an individual with a middleear infection, as often occurs in young children.

The anatomy of the ear canal 118 and the tympanic membrane 122 is quitevariable across individuals of different ages, and even among those ofthe same age. The length and diameter of the ear canal 118 may vary, aswell as its shape. Further, the size and position of the tympanicmembrane 122 is not constant. Accordingly, it would be useful fortreatment of middle ear infection, to be able to develop a system fordelivering and maintaining fluid in the ear canal for treatment of theear canal or tympanic membrane that would be comfortable for the patientand would prevent fluid from leaking out of the ear canal. One such usefor the system would be for anesthetizing the tympanic membrane prior todelivery of tympanostomy tubes.

FIG. 2 shows a system for delivering and maintaining fluid in the earcanal for anesthetizing the tympanic membrane using an iontophoresisdelivery system according to one embodiment of the invention. Theiontophoresis ear kit system 200 consists of a cable 210, control unit228, a fill tube and wire system 212 including handles (grips) 214 a and214 b, and iontophoresis electrodes (not shown). The system is designedto fill and retain solution in the ear canal and deliver electric chargeto the ionized drug solution. Additionally shown in FIG. 2 are a set ofearplugs 220 a-e, a syringe 222 for attachment to the luer connectors224 a and 224 b on the fill tube and wire system 212, and returnelectrode 226. FIG. 2 further shows an iontophoresis control unit 228, awire and tube management unit 230, in this case a tie, and a set ofearplug sizers 232.

Turning now to a more detailed explanation of the system shown in FIG.2, the set of ear plug sizers 232 are shown with 5 earplug sizers 234 a,234 b, 234 c, 234 d, and 234 e that will aid in determining which sizeearplug will best fit the patient's anatomy. The earplug sizers 234 a-eare provided with lugs 236 a-e and ear plugs 220 a-e. In theillustrative embodiment, there are 5 different earplug sizes, but inother embodiments there may be 1, 2, 3, 4, 6, 7, 8 or even more than 8earplug sizes. The lugs 236 a-e are constructed, for example, of a rigidplastic material for insertion past the concha 104 (see FIG. 1A) andinto the ear canal (118) for initial selection of the size of theearplugs 220 a-e. The outer diameters of the lugs are equivalent to thesealing diameters of the earplugs. In an alternative embodiment, thelugs may be constructed of a flexible material such as silicone rubberand have the same shape as the ear plugs.

An exemplary earplug 300 is further shown in FIG. 3. The earplug 300 isdesigned to provide adequate surface area for the placement ofsufficient adhesive for sealing of the ear canal, and to provide for afeature that will allow for easy removal of the earplug 300 from the earcanal. Accordingly, the earplug is made of a flexible material that canconform to the contours of the ear canal and may be made of siliconerubber or other similar materials such as polyurethane, styrenebutadiene, butyl and fluorosilicone rubbers. As can be further seen inFIGS. 4 and 5, each earplug 300 is constructed of a dome shaped 302distal portion 312 for insertion into the ear canal 118 and orientationtoward the tympanic membrane 122 (see FIG. 1B) and a proximal portion314. The proximal portion 314 of the dome 302 has a flange 304 thatsurrounds it. Further, a shaft section 318 disposed within the domeshaped section 302 can be attached at its distal end to the distal endof the dome shaped section 302 and at its proximal end 328 to theearplug sizer 234 a-e (See FIG. 2) or to the outside surface of thehandle 316 which contains the electrode.

The earplug 300 provides a seal to keep liquid in the ear canal for aperiod of time of at least about 1 minute, often at least about 5minutes, often at least about 10 minutes, often at least about 30minutes and often at least about 60 minutes. In some cases, the liquidis a drug solution useful for anesthetizing the tympanic membrane. Theearplugs include an adhering substance for adhering the earplugs to theear canal. The adhering substance must adhere to the earplug substrateas well as the outer ear canal skin (the concha, see FIG. 1A). Theadhering substance must be more adhesive to the earplug 300 than to theconcha 104 and must allow for peeling off and repositioning of theearplug 300 within the ear canal and further must adhere to both wet anddry skin. The adhering substance may be a two-sided tape or a pressuresensitive adhesive. In a particular embodiment, the earplugs are coatedwith a pressure sensitive adhesive (PSA) 320 that secures them in theear canal. Representative pressure sensitive adhesives include but arenot limited to silicones, acrylics, butyl rubber, ethylene-vinylacetate, natural rubber, nitriles and styrene block copolymers, and inparticular may be silicone rubbers manufactured by Dow-Corning under thetrade names of MD7-4602 or MD7-4502 or manufactured by NuSil Corporationunder the trade name of MED-1356. Multiple color-coded earplug sizes areavailable to accommodate variation in ear canal size.

The earplugs 300 are designed to have a dome shape 302 and a flange 304surrounding the dome 302. The flange may further have a flap 306 whichextends beyond the circumference of the rest of the flange. The PSA maybe applied in bead form, ring form or brushed on. In the embodimentshown in FIG. 5, three rings 308 of PSA surround the proximal portion314 of the dome. The PSA 320 may be applied in 1 or more rings (1, 2, 3,4 or 5) often in 3 rings, or 2 to 4 rings or even 1 to 5 rings. In oneaspect, the PSA may be applied to the earplug 1400 in a patterned manneras shown in FIG. 14A with two thin bands 1402 and 1404 on one side of athicker band 1406 and two thin bands 1408 and 1410 on the other side ofthe thicker band 1406 and to the earplug 1420 in a contoured manner 1422as shown in FIG. 14B, such that the earplug 300 can be positioned beforethe PSA is in contact with the skin. Further, the PSA may be applied ingreater quantity in certain areas to match the anatomical structureswithin the ear. The PSA 320 may also be applied in partial rings or inspots. The PSA 320 can be applied either to the dome section 302 of theearplug 300 or the flange section 304 of the earplug 300 or to both theflange and the dome sections of the earplug. The PSA 320 sticks to theear canal walls and the outside ear and provides retention for theearplug 300. It prevents the iontophoresis drug solution from coming outof the ear.

Prior to insertion of the earplug 300 into the ear canal, a liner may beused to protect the PSA from adhering. The liner is removed prior tofinal placement of the earplugs. In an alternative embodiment, theadhesive formulation may be replaced with a formulation that is modifiedto contain groups or chemical moieties that will change their tack tothe skin upon application of an external signal. This signal may bechemical (such as presence of absence of a solvent that causesswelling), thermal (lowering or increase of temperature), electrical,mechanical (change in stress or strain), magnetic or optical. The changein surface adhesive property (amount of adhesive force between adhesivelayer and skin) would occur upon application of the external signal,thereby allowing for replacement or repositioning of the earplug 300 inthe ear canal.

An example of a system that can change in response to an external signalis the use of a solvent system that is volatile at body temperatures(for easy removal). The presence of solvents (including but not limitedto alcohols or ketones, more specifically a mixture of alcohol andde-ionized water or low boiling point alcohols such as ethanol orisopropyl alcohol or a solvent such as acetone) lowers the adhesion bymaking the polymer molecules highly mobile and leads to lowerinteraction with the substrate. Removal of the solvent would lower themobility and lead to a higher degree of interaction between the polymerchains in the adhesive and the substrate, thereby leading to a higheradhesive force.

In an alternative embodiment, the adhesive may be replaced withself-expanding sections on the earplugs themselves. These self-expandingsections may be made from any self-expanding material, including but notlimited to polymeric materials, and metallic materials such as nitinolin the form of a ring attached to the earplug.

The flange 304 can be designed to be a continuous 360 degree flange thatsurrounds the earplug dome 302 or it can have notches or cuts atdifferent locations for relieving stress on the earplug 300 or forpreventing pleating when the earplug 300 is compressed prior to beinginserted in the ear canal or while positioned within it. In addition, asshown in FIGS. 11A, 11B, 11C, 11D and 11E, the flange 304 may have anumber of different configurations including but not limited to a conchashape 1100, to follow the contour of the concha (FIG. 11A), a threefinger design 1102 (FIG. 11B), an oval two finger design 1106 and arectangular two finger design 1108 (FIGS. 11D and 11E) and a roundflange design 1104 with no flaps or fingers (FIG. 11C). In addition tothe two finger designs 1106 and 1108 and three finger design 1102 shown,any number of fingers from 4 to 6 fingers or more are contemplated.Additionally, the earplug may be designed to fit over the tragus 114alone or to both the concha 104 and the tragus 114 (see FIG. 1A). Wherethe earplug is designed to fit over the concha 104, the earplug mayinclude trim lines, such that the earplug may be trimmed alongpredetermined portions to an appropriate earplug for the size and shapeof a particular patient's concha.

FIG. 3 shows the flange 304 with 4 notches 322 a, b, c and d, but theflange may have any number of notches such as 1, 2, 3, 5 or 6 notches.It can also be designed to be less than 360 degrees to partiallysurround the dome shaped portion such as from 180 degrees to less than360 degrees. The flap 306 is an aid that allows for the ease of removalof the earplug 300 from the ear canal. The flap 306 allows the healthcare professional to peel the plug from the ear canal. It can bedesigned to be an integral part of the earplug or a separate componentand attached to the earplug 300 rather than molded with the earplug. Asshown in FIG. 5 an exemplary dome shaped ear plug 300 has a sealingdiameter (SD) 324 that fits against the ear canal for sealing theiontophoresis solution into the ear canal. The flange 304 provides anadditional area for presence of PSA 320 and helps in increasing thesurface area for PSA 320. The PSA application on the earplug helps insticking the plug to the ear canal walls. The notches 322 a-d on theflange 304 help reduce the pleating in the flange 304 which may occurduring insertion and retention in the ear canal due to the oval natureof the ear canal in some people. The flap 306 is designed to be easy togrip, non-intrusive and comfortable. Pulling on the flap 306 leads topeeling of the earplug 300, allowing for comfortable removal of theearplug 300 from the ear canal.

Use of PSA to secure the earplug serves to eliminate the need forfurther retention elements like a headset. PSA application is a processchallenge because of the three dimensional geometry of the earplug. Themethod of using a dispensing system similar to the one manufactured byEFD Corporation to apply beads of the adhesive as well as the method ofbrushing the PSA on the earplug enhances the manufacturability of theearplug.

The flange 304 provides an additional area for presence of PSA 320 andhelps in increasing the surface area for PSA 320. The PSA application onthe earplug helps in sticking the plug to the ear canal walls. Thenotches 322 a-d on the flange 304 help reduce the pleating in the flange304 which may occur during insertion and retention in the ear canal dueto the oval nature of the ear canal in some people. The flap 306 isdesigned to be easy to grip, non-intrusive and comfortable. Pulling onthe flap 306 leads to peeling of the earplug 300, allowing forcomfortable removal of the earplug 300 from the ear canal.

In an alternative embodiment, an adjustable ear plug design may bedesirable, and that may require the use of pressure sensitive adhesiveor may not require such use. The design is shown in FIG. 12 and includesan earplug 1200, an earkit handle 1202, a lever 1204, and a flap 1206.The flap 1206 is shaped like an umbrella and is made of an elastomerwith higher durometer than the earplug 1200. In use, the flap 1206engages the inner surface 1208 of the earplug 1200. The lever 1204 isengaged with the earkit handle 1202 in a threaded fashion. Followinginsertion into the ear canal, there will be a slight clearance betweenthe earplug 1200 and the ear canal. The lever 1204 is then rotatedclockwise to advance the lever 1204 toward the ear drum. As the leveradvances forward, it opens the flap 1206. The flap 1206 presses againstthe inner surface 1208 of the earplug 1200 and stretches the earplug1200 to fit against the ear canal. Using a buttress thread as thethreaded interface between the lever 1204 and the handle 1202 reducesthe possibility of backward movement of the earplug 1200, ensuringcontinued sealing of the ear canal.

Excessive pressure buildup in the ear canal can cause patient discomfortand is not desirable. To prevent excessive pressure buildup the ear kithandle 316 is designed to include vent features 326 (which can includebut are not limited to holes or slits or a combination thereof) whichprovide a pathway for venting the air and fluid during iontophoresissolution delivery. In the embodiment shown in FIG. 5, the vent featurescomprise holes which can vary in diameter from 0.005 inches to 0.030inches. Depending on the maximum pressure requirements either one holeor multiple holes (2 are shown but there can be 3, 4 or more) can bepositioned along the handle (see FIG. 5). Furthermore, the interferencebetween the earplug shaft 318 and the ear kit handle 316 can be varieddepending on the maximum pressure requirements. The vent features 326are covered by the earplug shaft 318 and the earplug shaft 318 acts likea valve to allow for venting when the physician is filling the ear canaland prevents leakage when the therapy is on-going.

The handle 316 is designed to allow for ergonomic gripping of the devicefor ease of insertion of the earplug 300 into the ear canal. The grip330 is designed as a rounded elbow, however it could be flat andrectangular as well, so long as it is easy to grip and small enough notto interfere with the operation of the fill tube and wire system 212.The handle 316 distal end 332 also includes mating features forinterfacing with the earplug 300 and a cavity for positioning andseating the electrode. The fill tube and wire system 212 is designed toinclude one or more spray holes and extends from the handle about 0.4inches. It is shaped to route behind the ear (see FIG. 6) and has luerconnectors 224 a and 224 b for easy connection and removal of thesyringe 222. The electrode (not shown) is a coiled silver wire thatresides inside of the handle 316 and provides adequate surface area forthe iontophoresis reaction.

FIG. 6 shows the earplug 300 seated on the handle 316 with the fill tip310 extending through the shaft section 318 of the earplug 300 andbeyond the distal portion 312 of the dome 302. The three spray holesdistributed 120 degrees apart on the fill tip 310 provide for solutionturbulence when filling the ear canal. There may be any number of sprayholes between 3 and 12, for example 4, 5, 6 or more spray holes that aredistributed about the fill tip 310. The number of spray holes range fromone to three or more and are evenly distributed one from the other(where there are three spray holes, they are spaced 120 degrees apart)to create turbulence in the ear canal 118. Further, the most distalportion of the fill system tip 310 is designed to face the tympanicmembrane 122 such that during iontophoresis, the ear canal fills fromthe portions closest to the tympanic membrane out towards the outer ear10 and air that has accumulated in the ear canal 118 will be evacuatedthough vent features 326 in the handle 316 as shown in FIG. 5. In analternative embodiment, a valve (such as a one way valve or a checkvalve) may be integrated into the handle 316 such that fluid isinstilled through the handle 316 and into the ear canal, and is thefluid is retained in the ear by the valve in the handle 316. No externalfill system would therefore be required.

FIG. 13A is another embodiment of the device according to the invention.In this embodiment, the iontophoresis system of the invention comprisesan earplug 1320, a fluid source 1340, a control unit 1342 and a groundpad 1346. Earplug 1320 is configured to be inserted into a patient's earand remain there throughout the iontophoresis procedure. Earplug 1320 ismounted on a handle 1322 that is configured to be gripped duringinsertion of earplug 1320 into a patient's ear. Earplug 1320 alsoincludes a flap 1328 that may be gripped and pulled to assist inremoving earplug 1320 from the patient's ear. Of course, these featuresare mere examples, and any other suitable kinds of gripping features maybe incorporated into earplug 1320. While only one earplug 1320 is shown,it should be understood that the iontophoresis system 1300 may have twoearplugs 1320 that may be used simultaneously or sequentially.

As best seen in FIG. 13B, earplug 1320 includes a flexible sealingelement 1324 and a distally projecting nozzle 1326. Sealing element 1324is configured to provide a fluid tight seal against the patient's earcanal when earplug 1320 is inserted in the patient's ear canal. Nozzle1326 is positioned to project into the patient's ear canal when earplug1320 is inserted in the patient's ear canal, such that nozzle 1326 isspaced lateral to the tympanic membrane (TM). Nozzle 1326 has sprayapertures 1327 and is secured to the distal end of a semi-rigid post1325. Post 1325 provides a path for fluid communication from conduit1320 to spray apertures 1327. Spray apertures 1327 are thus in fluidcommunication with fluid source 1340 via post 1325 and conduit 1330.Sealing element 1324 is secured to a rigid frame 1323 which definesgripping features on handle 1322. Sealing element 1324 and frame 1323also together define a working channel 1321. Frame 1323 defines aplurality of vent paths 1329 in fluid communication with working channel1321. Vent paths 1329 are configured to allow air to escape workingchannel 1321 while working channel 1321 fills with iontophoresissolution, yet are further configured to prevent iontophoresis solutionfrom escaping working channel 1321 via vent path 1329 once workingchannel 1321 is filled with iontophoresis solution. An iontophoresiselectrode 1352 in the form of a coil extends along at least part of thelength of working channel 1321. It should be understood thationtophoresis electrode may have any other suitable configuration.Iontophoresis electrode 1352 is coupled with control unit 1342 via acable 1350 and is thereby operable to be activated with a positivecharge. Thus, control unit 1342 may activate iontophoresis electrode1352 to provide a repulsive electromotive force to the iontophoresissolution delivered through aperture 1327 to drive the anesthetic of theiontophoresis solution into the tympanic membrane TM for anesthetizationof the tympanic membrane.

Turning now to FIG. 15, in a particular embodiment, the earplug assembly1500 is shown with a dome shaped earplug 1502, without a flange, butwith a flap 1504 that can be gripped to remove the earplug from the earcanal as described above. In this particular embodiment, dual lumentubing 1506 made of a soft polymeric material (in certain embodiments ofPea of 20 to 60 durometer) may be used to fill the ear canal withiontophoresis solution (the first lumen 1508) and to contain theiontophoresis wiring (the second lumen 1510). The handle 1512 isconstructed such that the tubing is routed through the handle and exitsthe handle at an angle of between about 10 and 30 degrees and oftenabout 15 degrees. The tubing is forced into the groove 111 behind thehelix 108 of the ear 10 (see FIG. 1A). The tubing 1506 is then routedover the ear and terminates in a coiled section 1370 (see FIG. 13A). Asleeve 1550, made of higher durometer material that is smooth andslippery (in certain embodiments a polyolefin heat shrink thermoplasticmaterial with a durometer above 50), may be included in a coaxialmanner, surrounding a portion of the tubing 1506 above the ear, suchthat the earplug system 1320 may comfortably conform to differentanatomies, that is, different ear sizes and head shapes and distributethe forces over a larger area above the ear, by allowing the tubing 1506to slip within the sleeve 1506 and vary the amount of tubing 1506 thatresides between the earplug 1502 and the polymeric sleeve 1550. A clipmay be attached to the end of the coiled section 1370 and is clipped tothe patient's clothing such that tension is applied to the earplugsystem 1320, protecting the system 1320 from interference by the patientor treatment provider and interruption of the iontophoresis procedure.

As noted earlier and shown in FIGS. 14A and 14B, pressure sensitiveadhesive is applied to the dome shaped earplug 1502 in a variety ofpatterns. A pressure applicator 1514 is included on the inside portion1516 of the dome shaped earplug 1502 and the handle 1512 is insertedinto the base 1518 of the pressure applicator 1524. The pressuresensitive adhesive (PSA) is activated once it is in position in the earcanal by displacing or rotating handle 1512 and thereby putting pressureon the inside portion 1516 of the dome shaped earplug. As is shown inFIGS. 16A, 16B, 16C, and 16D, the base portion 1518 of the pressureapplicator 1514 is shaped to match the ear canal anatomy. In thesmallest sizes 1610 shown in FIG. 16D, the base portion 1620 is round,in the largest sizes 1616, the base portion 1626 is oval, the middlesizes 1612 (FIG. 16C) and 1614 (FIG. 16B) increase in ovalness fromsomewhat oval 1622 to mostly oval 1624 as the earplugs increase in size.The smallest earplugs may not require a pressure applicator as the gapbetween the handle stem and the umbrella portion of the plug is smallenough that the handle stem can be deflected to active the glue bypivoting the handle.

As noted above with regard to earplug 300, a liner may be used toprotect the PSA from adhering. The liner may be removed prior to finalplacement of the earplugs or it may be removed once final placement hasbeen determined This latter type of liner is shown in FIGS. 17A and 17B.The liner 1700, shown in FIG. 17A is used to protect the PSA duringstorage and during insertion of the earplug 1750, shown in FIG. 17B. Theliner has a gripping feature 1702 and an adhesive protector 1704. Theliner may act as an insertion aid, giving the treatment provider theability to reach a desired location before activating any of the PSA. Inthis way, the treatment provider can reposition and reinsert theearplug. As shown in FIG. 17B, the liner 1700 is designed to wrap aroundthe profile of the dome of the earplug 1750 and fold back over ontoitself In order to expose the PSA to the skin, the gripping feature 1702is pulled back, rolling back the adhesive protector 1704, and allowingthe PSA to touch the skin of the ear canal. In the embodiment shown inFIG. 17A, two liners 1700 are used to protect the PSA, but any number ofliners from 1 to 4 may be used according to the invention.

The method according to the invention is carried out according to FIG.8. The anesthetizing solution is prepared (in this case a solution of1:12,000 epinephrine, 3.3% lidocaine and 0.7% sodium bicarbonate but maybe any appropriate combination thereof such as lidocaine, lidocaine plusepinephrine, or lidocaine plus epinephrine and sodium bicarbonate orother anesthetizing solution known in the art) and warmed to bodytemperature (800).

The ear canal is cleaned and prepared (810) using a standard earcleaning technique, making sure that the tympanic membrane is notblocked by cerumen of observable size, The outside of the ear canal iswiped as well as the opening of the ear canal with rubbing alcohol toremove any oils or wax from the skin. The site is allowed to dry.

The ear canal can be filled with anesthetizing solution in a number ofdifferent ways. The ear canal can be filled first by using a manual fillnozzle and then the earkit system 200 can be inserted to seal the earcanal and keep the fluid in place. Other methods for filling the earcanal will be described below. Following filling of the ear canal, theiontophoresis ear kit system 200 is then prepared for placement on thepatient as follows. As previously described above with regard to FIG. 2,an earplug sizer 234 is placed into a patient's ear canal to determinethe appropriate earplug size for the size and shape of the patient's earcanal (820). The appropriate ear plugs 300 are removed from the package400 (see FIG. 7) and the PSA 320 is exposed. The package 400 is made soas to prevent any dust exposure of the adhesive and is designed in sucha way to enable the removal of the earplugs 300 with the grips 330 fromthe package 400 and placement onto the handles 214 a and 214 b. In theembodiment shown in FIG. 7, the package 400 is designed so that theearplug 300 is positioned with the dome portion 302 facing up such thatthe adhesive is not in contact with any portion of the package. In analternative design, the dome portion may be seated in a cup-shapedpackaging system, such that the adhesive is in contact with the package.The earplugs 300 are then positioned onto the handles 214 a or 214 b ofthe fill tube and wire system 212 (830). In an alternative embodiment,using the earplug system 1320 shown in FIG. 13A, the device is placed inthe ear canal, the ear canal is filled with the iontophoresis solutionthat is supplied through the dual lumen tubing 1304 and theiontophoresis procedure is continued as further described below.

The earplugs 300 are carefully placed into the patient's ears such thatthe ear canal is sealed against leakage of fluid from the ear canal(850). The fill tube and wire system 212 are routed behind the ear andanchored behind the patient's head such that they remain out of thepatient's and treatment provider's way. The return electrode patch 226is connected to the iontophoresis ear kit system 200 via the returnelectrode snap 227 on the electrode patch 206 and the return electrodeconnector (not shown) on the cable 210. The syringe is depressed inorder to fill the ear canal with anesthetizing solution (860). Thereturn electrode patch 226 is placed on the patient's skin and thecontrol unit 228 shown in FIG. 2 may be connected to the control unitconnector 229 on the fill tube and wire system 212 shown in FIG. 2 andthe control unit 228 may be clipped to the patient's or the parent'sclothing.

The battery tab located on the back of the control unit 228 case isremoved. Empty status bars should appear on screen once the device ispowered on. To start the iontophoresis procedure, the control unit isactivated by pressing the yellow button and/or the blue button on thecontrol unit 228 and holding for 2 seconds (870). Each button controlsan independent channel, with button colors corresponding to the colorsof the left and right sides of the headset. A short beep confirms when abutton has been activated. The control unit 228 is clipped to thepatient's or the parent's clothing. The status bars will fill up toindicate each channel's progress toward completion. A typical proceduretakes approximately 10 minutes, with each status bar segmentrepresenting approximately 20% of procedure time. A flashing segmentindicates that current is running; a solid segment indicates the portionalready completed. To pause the procedure, the button for theappropriate channel is pressed and held for 2 seconds. The pause symboland status bar segment will both flash and then turn solid when currentdelivery has stopped. To resume the procedure, the same button ispressed and held for 2 seconds. The control unit 228 will play a longbeep when each channel (yellow or blue side) has completed delivering afull dose. The status bars will also turn completely solid to indicatethat full charge has been delivered through each channel. Once thetympanic membrane is anesthetized, to deactivate the control unit, thebutton for the appropriate channel is pressed and held for 2 seconds.

Other methods of filling the ear canal will further be described withregard to FIGS. 9A, 9B, 9C and 9D and FIGS. 10A, 10B, 10C, 10D and 10E.As shown in FIGS. 9A, 9B, 9C and 9D, the earplug 900 can be inserted byusing an earplug insertion tool (not shown in the figure) and thensecured and sealed to the ear canal (see FIG. 9A). The ear canal canthen be filled with the drug solution using a manual fill system 902 orany other means of filling the ear canal, by inserting the fluid throughthe central lumen 904 of the earplug 900 (FIG. 9B). The central lumen902 of the earplug 900 can then be sealed by inserting the elbow-handle906 through the lumen (FIG. 9C). The tube and the wire 908 can then berouted behind the ear (FIG. 9D)

In another method for filling ear canal according to the invention, anearplug 1000 can be loaded on to a speculum 1002 as shown in FIG. 10A.The speculum 1002 can then be used for positioning and insertion of theearplug 1000 in the ear canal (see FIG. 10B). After the earplug isseated in place the ear canal can be filled with fluid by using thespeculum as an aid and guide and filling with a manual fill system 1004(FIG. 10C). After the ear canal has been completely filled with thefluid solution, the speculum 1002 can be removed, keeping the earplug1000 in place (FIG. 10D). The ear kit handle 1006 can then be insertedin the earplug 1000 to seal the earplug and provide contact between thedrug solution and the electrode present in the ear kit handle 1006 andthe tube and wire 1008 can be routed behind the ear (FIG. 10E).

In a further aspect, the fill tube and wire system 212 may be useful fordelivering a drug solution to the ear canal for treating the ear canalIt may be used for anesthetizing the ear canal or tympanic membrane orfor delivering solutions for other therapeutic purposes. Such solutionsinclude but are not limited to antifungal or antibacterial agents suchas benzalkonium chloride, boric acid, acetic acid, and clotrimazole,anti-inflammatory agents such as beclamethazone and antibiotic andsteroids such as betnesol, prednisilone sodium phosphate, gentamycin,neomycin, and quinolenes, astringent agents such as aluminum acetate,ceruminolytics such as sodium chloride solution, hydrogen peroxide orsodium bicarbonate solution.

The invention has been described with reference to certain examples orembodiments of the invention, but various additions, deletions,alterations and modifications may be made to those examples andembodiments without departing from the intended spirit and scope of theinvention. For example, any element or attribute of one embodiment orexample may be incorporated into or used with another embodiment orexample, unless otherwise specified or if to do so would render theembodiment or example unsuitable for its intended use. Also, where thesteps of a method or process have been described or listed in aparticular order, the order of such steps may be changed unlessotherwise specified or unless doing so would render the method orprocess unworkable for its intended purpose. All reasonable additions,deletions, modifications and alterations are to be consideredequivalents of the described examples and embodiments and are to beincluded within the scope of the following claims.

The invention claimed is:
 1. An earplug comprising: a dome-shapedportion for insertion into an ear canal, said dome-shaped portion havingan outside surface and an inside surface; a pressure sensitive adhesivepositioned on the outside surface of the dome-shaped portion andconfigured to contact a surface of the ear canal to define a space inthe ear canal between the dome-shaped portion and a tympanic membranesuch that a solution delivered into the space can be retained in thespace for a period of time; and a liner in a folded configurationconfigured to protect the pressure sensitive adhesive when thedome-shaped portion with the pressure sensitive adhesive positionedthereon is inserted into the ear canal, the liner configured to unfoldafter the dome-shaped portion is positioned in the ear canal such thatthe pressure sensitive adhesive is exposed for contact with the surfaceof the ear canal.
 2. The earplug of claim 1, further comprising a flangesurrounding the dome-shaped portion.
 3. The earplug of claim 2, whereinthe flange surrounds 180 to 360 degrees of the dome-shaped portion. 4.The earplug of claim 2, wherein the flange includes notches.
 5. Theearplug of claim 1, wherein the solution includes at least one of: ananesthetizing solution, an antibacterial solution, an antifungalsolution, an anti-inflammatory solution, or a ceruminolytic solution. 6.The earplug of claim 5, wherein the solution is an anesthetizingsolution including at least one of: lidocaine; a combination oflidocaine and epinephrine; or a combination of lidocaine, epinephrine,and sodium bicarbonate.
 7. The earplug of claim 1, further comprising ashaft portion for connection to a fill system through which the solutionis delivered into the space in the ear canal, the dome-shaped portionsurrounding a portion of the shaft portion.
 8. The earplug of claim 1,wherein the pressure sensitive adhesive includes at least one of: asilicone, an acrylic, butyl rubber, ethylene-vinyl acetate, naturalrubber, a nitrile, or a styrene block copolymer.
 9. The earplug of claim1, wherein the liner has (1) a first portion that is configured to wraparound a portion of the dome-shaped portion to cover the pressuresensitive adhesive and (2) a second portion that is configured to foldover and onto the first portion.
 10. The earplug of claim 1, wherein theliner includes a gripping element configured to be pulled to unfold theliner and remove the liner from the earplug.
 11. A system, comprising:an earplug for use in retaining a solution in an ear canal of the humanpatient, the earplug comprising: a dome-shaped portion for insertioninto the ear canal, the dome-shaped portion having an outside surfaceand an inside surface; and a pressure sensitive adhesive positioned onthe outside surface of the dome-shaped portion and configured to contacta surface of the ear canal to define a space in the ear canal betweenthe dome-shaped portion and a tympanic membrane such that the solutioncan be retained in the space for a period of time; a fill systemconfigured to deliver the solution into the space in the ear canal; anda liner including a gripping element, the liner configured to protectthe pressure sensitive adhesive when the dome-shaped portion with thepressure sensitive adhesive positioned thereon is inserted into the earcanal to enable the dome-shaped portion to be positioned in the earcanal before the liner is removed by pulling on the gripping element.12. The system of claim 11, further comprising vent features.
 13. Thesystem of claim 12, wherein the vent features include at least one of: avent hole or a vent slit.
 14. The system of claim 11, further comprisinga flange surrounding the dome-shaped portion.
 15. The system of claim11, wherein the fill system further includes a fill tip including aplurality of spray holes.
 16. The system of claim 11, wherein thesolution includes a therapeutic agent, the system further comprising anelectrode to supply a current to drive the therapeutic agent, viaiontophoretic delivery, into the tympanic membrane.
 17. A method,comprising: positioning a dome-shaped portion of an earplug in an earcanal of a human patient, the dome-shaped portion configured to fitagainst a surface of the ear canal and including a pressure sensitiveadhesive positioned thereon, the pressure sensitive adhesive covered bya liner; removing, after the dome-shaped portion is positioned in theear canal, the liner by rolling back a portion of the liner to exposethe pressure sensitive adhesive such that the dome-shaped portionadheres to the surface of the ear canal; delivering, via a fill system,a solution including a therapeutic agent into a space between theearplug and a tympanic membrane; and supplying an electric current tothe solution to deliver the therapeutic agent to the tympanic membrane.18. The method of claim 17, wherein the therapeutic agent includes atleast one of: lidocaine; a combination of lidocaine and epinephrine; anda combination of lidocaine, epinephrine, and sodium bicarbonate.
 19. Themethod of claim 17, further comprising, prior to delivering the solutioninto the space, warming the solution to body temperature.
 20. The methodof claim 17, wherein the liner includes a gripping element, and theremoving the liner includes pulling on the gripping element such thatthe portion of the liner covering the pressure sensitive adhesive isrolled back to expose the pressure sensitive adhesive.